In the shipping of paper goods, such as envelopes, it is good practice to make use of a corrugated board tray which can be erected from a flat blank. This is because, after the envelopes have been used, the tray can be dismantled and stored or returned to the envelope manufacturer. It has been found that these open top trays sometimes allow dust and dirt to fall into the contents and sometimes they are even subjected to rain and snow. For that purpose, it would be desirable to provide a cover to extend over the top of a tray or a group of trays to protect the contents. Such a cover can also serve to lock together a plurality of trays, so that they can be handled as a unit. In the optimum case, such a cover would be constructed so that it could be dismantled and shipped back in flat form also. Attempts in the past to provide such a cover have been less than successful, primarily because of the high cost and because of the fact that the prior art constructions have been relatively intricate and fragile. These and other difficulties experienced with the prior art constructions have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a cover for a rectangular tray, which cover is capable of being disassembled and shipped in flat form.
Another object of this invention is the provision of a reusable cover formed of corrugated material, the cover having no elements that are easily damaged during shipment.
A further object of the present invention is the provision of a cover having a top panel and four walls for completely protecting an open tray or unitizing a plurality of trays.
It is another object of the instant invention to provide a cover for an open tray which is simple in construction, which is inexpensive to manufacture, and which is capable of repeated use with a minimum of care in its shipment.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.